Machines have been developed for plucking the feathers of poultry for use in poultry processing plants. These picking machines typically have drums and/or discs to which resilient rubber or synthetic picker fingers are mounted. The drums or discs are positioned along each side of a path of travel along which birds are conveyed. The drums or discs are then rotated at speeds as high as 600 to 1250 rpm causing the resilient fingers to be constantly driven into contact with the birds. Frictional forces between the rubber fingers and the feathers remove the feathers from the bird. However, the fingers tend to wear quickly, with an average processing line requiring replacement of from 8,000 to 10,000 fingers per month. With many processing plants running 3 or more processing lines, it is not atypical for a plant to replace one half million fingers per year.
The picker fingers typically have an enlarged disc-shaped base formed with an annular recess from which base a tapered, furrowed shank extends. Each finger is installed in a disc with the annular recess of the finger base located within a hole in the support disc or drum (hereinafter referred to as “disc”) with the recess edges abutting and therefore gripping opposite sides of the rim about the hole of the support disc. The finger shank adjacent the annular recess is oversized, i.e., larger than the hole in the support disc, in order to prevent the finger from becoming dislodged when the discs are brought up to operating rotational speeds. However, this oversized arrangement results in substantial difficulty when removing and replacing fingers. Worn fingers are removed from the disc by cutting the finger at its annular recess. The two pieces can then be removed with relatively little effort. A new finger is installed by passing its shank portion from behind the disc through the enlarged hole in the disc until its tapered surface adjacent its enlarged base engages the rim about the hole. The shank is then pulled with a substantial degree of force in order to seat the annular recess about the edge of the hole.
It is inherently difficult to seat the picking fingers within the disc holes manually due to the amount of force required in pulling their base portions into the support holes. Due to the orientation of the discs within the processing machinery, it is often difficult to reach the fingers that need to be replaced. Not only is a substantial amount of strength required but also the space available in which to work is usually quite restricted making it awkward to exert the force needed to properly seat the annular recess about the hole edge. Carpal tunnel syndrome, tendonitis, and other stress related injuries are common among operators who routinely change fingers.